Position adjusters for seat backs



Sept. 6, 1966 P. c. TABOR POSITION ADJUSTERS FOR SEAT BACKS 2Sheets-Sheet 1 Filed June 22, 1964 FIG. 2.

INVENTOR.

PAUL (I 72780 Sept. 6, 1966 P. c. TABOR 3,271,071

POSITION ADJUSTERS FOR SEAT BACKS Filed June 22, 1964 2 Sheets-Sheet 2FIG. 7

l/l/I/ /d INVENTOR.

PAUL 0. T4501? 7 ATTORNEYS FIG. 5

United States Patent 3,271,071 POSITIGN ADJUSTERS FOR SEAT BACKS Paul C.Tabor, Clawson, Mich., assignor, by mesne assignments, toRockwell-Standard Corporation, a corporation of Delaware Filed June 22,1964, Ser. No. 37 6,775 4 Claims. (Cl. 297-375) This invention relatesto seats with reclining backs and, more specifically, to novel positionadjusters capable of positioning the backs of such seats in an infinitenumber of inclined positions.

Position adjusters for reclining seat backs are well known and arewidely employed in automobiles, buses, and the like. The majority of theheretofore available position adjusters are equipped with ratchet andpawl mechanisms which provide a limited number of adjusted positionsdepending upon the number and spacing of the teeth on the ratchet. Suchposition adjusters, in addition to having only a small number ofadjusted positions which cannot be altered by the user, are noisy andsubject to rapid wear. A need has, therefore, long existed for positionadjusters having a wider range of adjustment, quiete operation, and alonger service life.

One attempt to satisfy this need entails the use of a hydraulic pistonand cylinder arrangement which has proved too expensive to becommercially feasible particularly because of requirements forpreventing leakage of the hydraulic fluid. Other proposals, including anextensible rod arrangement which is selectively locked or released bymovement of a tiltable washer construction, have in general lacked thenecessary compactness, lightweight, dependability and low cost which arenecessary to satisfy the requirements of commercially practicalapplications.

It is an important object of the present invention to provide novelimproved position adjusters which do not have the above-discusseddisadvantages of those heretofore known.

In its preferred embodiment, the novel position adjuster provided by thepresent invention for accomplishing the foregoing object includes anelongated housing, an extensible tension member mounted in andprotruding from the housing, and a plurality of wobble type lockingplates which surround and are normal-1y tilted against the tensionmember and prevent it from being extended relative to the housing. Alever opea-rted cam permits the locking plates to be tilted from thenormal locking position about a fulcrum pin to free the tension memberfor movement relative to the housing.

The housing and tension member are attached to the seat portion and seatback of the seat with which the position adjuster is employed.Consequently, by varying the extension of the tension member from thehousing in the manner described above, the seat back can be positionedin any one of an infinite number of positions relative to the seatportion within a wide range of adjustment. Moreover, these novelposition adjusters operate noiselessly, are substantially less subjectto wear than those of the ratchet and pawl type or the type shown in theBrandoli patent, and are much cheaper to manufacture than the Brandoliposition adjuster would be.

From the foregoing it will be apparent other objects of the presentinvention include the provision of novel position adjusters forreclining seat backs which:

(1) Are capable of positioning the seat back in an infinite number ofpositions relative to the seat portion;

(2) Operate noiselessly;

(3) Are less susceptible to wear than those heretofore available;

(4) Are simple and relatively inexpensive to manufacture; and

(5) Positively prevent movement of the seat back away from the seatportion (i.e., in the reclined direction), but merely brake movement ofthe seat toward the seat portion, permitting the seat to be adjusted inthis direction without releasing the position adjusters lockingmechamsm.

Another importnt object of the present invention is the provision ofseats having a seat portion, a reclining back, and :a position adjusterfor positioning the seat back in any of an infinite number of tiltedpositions relative to the seat portion.

Additional objects and further novel features of the present inventionwill become more fully apparent from the appended claims and as theensuing detailed descrip tion and discussion proceeds in conjunctionwith the :accompanying drawing, in which:

FIGURE 1 is a side view of the frame of a reclining back automobile seatof the bucket type provided with a position adjuster fabricated inaccord with the principles of the present invention;

FIGURE 2 is a perspective view of the seat frame and position adjusterof FIGURE 1;

FIGURE 3 is a longitudinal section through the position adjuster;

FIGURE 4 is a top view of the position adjuster;

FIGURE 5 is a transverse section through the position adjuster, takensubstantially along line 5-5 of FIGURE 6, and illustrates the shape ofthe release cam provided to unlock the position adjuster and permitadjustment of the reclining seat back;

FIGURE 6 is a fragment of FIGURE 3 to an enlarged scale, showing theposition adjuster locking mechanism in its locked condition; and

FIGURE 7 is a view similar to FIGURE 6, but with the locking mechanismreleased.

Referring now to the drawing, FIGURE 1 illustrates an automobile seatframe 10 of the bucket type including a seat portion 12 and a back 14,and a position adjuster 16 constructed in accordance with the principlesof the present invention for adjusting back frame 14 in any of aninfinite number of inclined or tilted positions relative to seat portionframe 12.

Seat frame 10 is of tubular construction and includes, in addition tothe frame 12 of the seat portion and frame 14 of the seat back, atransversely extend-ing rail 18 which overlies rear rail 20 of frame 12and is pivotally attached to the side rails 22 of frame 12 by brackets24 and pivot members 26 which may be bolts, studs, or the like.

As is best shown in FIGURE 1, brackets 28 welded to rail 18 areconnected by pivot pins 30 to cooperating brackets 32 fixed as bywelding to the lower rail 34 of seat back frame 14, mounting seat backframe 14 for pivotal movement relative to frame 12 of the seat portion.The height of seat back frame 14 relative to frame 12 may be varied byadjustable stops 36 which engage rear rail 20 of frame 12 and are fixedto rail 18 by nuts 38.

The use of an intermediate rail to mount seat back frame 14 permits theseat back to be folded against seat portion frame 12 without disturbingthe relative positioning between these components provided by positionadjuster 16.

The foregoing and other details are not important as far as the presentinvention is concerned and may be varied as desired as will shortlybecome apparent.

Referring still to FIGURES 1 and 2, the novel position adjusted 16 bywhich the inclination of seat back frame 14 is varied includes a housing40 pivotally connected to a bracket 42 fixed to seat back frame 14 bybolt 44 and nuts 46 and a tension member or rod 48 pivotally connectedto one of the two brackets 28 on rail 18 as by pivot pin 50. Tensionmember 48 is slidably guided in and protrudes from housing 40. A lockingmechanism identified generally by reference character 52 and housed inadjuster housing 40 prevents extension of tension mem' ber 48 relativeto the housing so that, with the locking mechanism in its normal lockedcondition, housing 40 and tension member 48 act as a single inextensiblelink, maintaining seat back frame 14 at the desired inclination relativeto seat portion frame 12.

With further reference now to FIGURES 3 to 5, the adjuster housing 40 iscomprised of two substantially identical flat rectangular side stampings54 and 56 positioned opposite each other in mirror image relationship toprovide a housing having side walls and an open top and bottom. At oneend of the housing side stampings 54 and 56 converge and meet inabutting relation to form the flange 58 fixed by bolt 44 to bracket 42.Stampings 54 and 56 are secured together as by welding to form a closureat this end of the housing. At the opposite end of housing 40, stampings54 and 56 are bent inwardly at right angles to form closure portions 60and 62 which overlap each other and are welded or otherwise securedtogether.

Tension member or rod 48 of the adjusting mechanism extends into housing40 through aligned apertures 64 in closure portions 60 and 62 and isprovided intermediate its ends with a groove 66 (FIGURE 6) whichreceives a retainer ring 68. Interposed between retainer ring 68 andclosure portion 60 is a coil spring 70 which surrounds tension member 48and continuously urges it inwardly of housing 40, i.e., toward flange 58at the opposite end of the housing.

The end of tension member 48 on the side of retainer ring 68 oppositespring 70 extends through apertures 72 in guide plates 74a and 7412which are mounted in housing 40 to keep rod 48 axially aligned relativeto the housing and to reinforce the housing so that it will not collapseunder load. The apertures 72 in guide plates 74a and 74b and apertures64 in housing closure parts 60 and 62 are coaxial.

Guide plates 74a and 74b are fixed in housing 40 by tabs 76 and 78extending from the guide plate through rectangular apertures 80 and 82in side stampings 54 and 56. After assembly of guide plate 74a inhousing 40, tangs 84 and 86, stamped from housing side members 54 and56, are bent as shown at the bottom of FIGURE 4 to assure a tightinterlocking fit of tabs 76 and 78 with the side stampings 54 and 56 andrigid connections between the guide plate 74a and the housing.

Guide plate 74a is provided with top and bottom flanges 88 and 90 whichextend normally from the main portion of the guide plate toward theretainer ring 68 on rod 48. Abutting the end of lower flange 90 andsurrounding tension member 48 are a number (five in the illustratedembodiment) of rectangular lock plates 92 of the wobble plate type whichare part of the locking mechanism 52 and which, when tilted intoengagement with rod 48, lock it against longitudinal movement relativeto housing 40 in a direction away from guide plate 74a. Lock plates 92have central apertures 94 which are slightly larger than the diameter oftension member 48 and allow the lock plates to be tilted against thetension member and a square external configuration which cooperates withside stampings 54 and 56 to prevent them from rotating in housing 40.

On the other side of lock plates 92 opposite but slightly higher thanlower flange 90 is a fulcrum pin 96 which extends across housing 40 andis secured in side stampings 54 and 56. Pin 96 provides the fulcrumpoint around which lock plates are tilted into engagement with tensionmember 48.

Lock plates 92 are tilted around fulcrum pin 96 by a coil spring 98extending between guide plate 74:: and lock plates 92 and surroundingtension member 48. Coil spring 98 biases lock plates 92 toward retainerdisc 68; and, as coil spring 98 exerts its entire force on lock plates92 at points above fulcrum pin 96, it pivots the lock plates in aclockwise direction about the fulcrum pin into engagement with thetension member. This causes the edges of lock plate apertures 94 to biteinto tension member 48, thus locking it against longitudinal movementrelative to housing 40 in a direction away from guide plate 74a.

Exertion of a load on seat back frame 14 tends to move tension member 48in the direction shown by arrow 100 in FIGURE 3. This tends to tilt lockplates 92 even further in a clockwise direction about fulcrum pin 96.Consequently the aperture edges exert a high unit load on tension member48. This load, multiplied by the coeflicient of friction between thelock plates and tension member 48 produces a high frictional forcebetween the axially fixed lock plates and the tension member, whichpositively locks the latter against extension from housing 40.

The locking arrangement just described does not positively lock tensionmember 48 against movement toward guide plate 74a which is advantageousin that it permits seat back frame 14 to be adjusted forwardly (i.e.,toward seat portion frame 12) without releasing the locking mechanism.However, the locking mechanism does exert a suflicient brakingresistance against movement of tension member 48 in this direction thatthe seat back will not be swung forward by sudden stops or the like.

The force which spring 98 exerts to lock rod 48 against movement by anaxial force acting on the rod (for example, the weight of a persons backon seat back frame 14) may be altered by changing the design of spring98 which is compressed in the assembly process by the bending of tangs84 and 86 to the position shown at the bottom of FIGURE 4. This movesguide plate 74a toward lock plates 92, thus shortening spring 98, whichbears against the normally axially immovable lock plates.

Tension member 48 is freed for movement relative to housing 40 to permitadjustment of seat back frame 14 by tilting lock plates 92 in acounterclockwise direction about fulcrum pin 96 until they areperpendicular to the tension member (see FIGURE 7). Since the apertures94 in the lock plates are larger in diameter than the tension member,this permits free movement of the tension member relative to thehousing. Lock plates 92 are tilted to this position against the bias ofspring 98 by a cam member 102 which extends across housing 40 and isrotatably supported by cam member journals 104 and 106 which extendthrough apertures 108 and 110 in side stampings 54 and 56. Journal 104terminates in a squared end 112 to which an operating lever 114 isattached. In the embodiment of the invention shown in FIGURE 1, lever114 is rocked by a pull wire 116 fixed to its free end.

With reference now to FIGURES 6 and 7, if it is desired to adjust seatback frame 14 away from seat portion frame 12 (i.e., rotate frame 14clockwise as shown in FIGURES 1 and 2, pull wire 116 is pulled in thedirection shown by arrow 118 in FIGURE 1. This rotates operating lever114 and cam member 102 counterclockwise, causing cam 120 of the cammember to exert a force on the lower part of the lock plates 92. Thisrotates the lock plates counterclockwise against the force of spring 98,forcing them into a position normal to tension member 48. This bringsthe apertures 94 of the lock plates into axial alignment with rod ortension member 48; and, as the apertures are slightly larger than thediameter of the tension member, the latter is free to movelongitudinally relative to housing 40, permitting seat back frame 14 tobe adjusted to the desired position. When pull wire 116 is released,spring 98 immediately rotates cam member 102 clockwise from the positionof FIGURE 7 to that of FIGURE 6 and tilts lock plates 92 into engagementwith tension member 48, thus locking seat back frame 14 in the adjustedposition.

Seat back frame 14 can also be adjusted in a counterclockwise or forwarddirection in the manner just described, if desired. Alternatively, theseat back frame can be adjusted in this direction by merely grasping itand pulling it in a counterclockwise direction against the braking forceexerted by the locking mechanism.

Although the principles of the present invention have been discussedparticularly as applied to automobile seats, it will be apparent to oneskilled in the art that they are by no means so limited in application.For example, it will be readily apparent that they are directlyapplicable to other kinds of reclining seats such as those employed inairplanes, buses, and passenger type railroad cars, for example. Theyare also directly applicable to reclining chairs and the like. The wordseat, as used in the claims of this application, is therefore to beunderstood as being employed in a generic sense to encompass theforegoing and other types of seating devices employing the presentinvention.

Also, it is not necessary that housing 40 of position adjuster 16 beconnected to seat back frame 14 as illustrated. The position adjusterwill work equally well with housing member 40 connected to the seatportion and tension member 48 connected to the seat back.

The present invention may be embodied in other forms without departingfrom the spirit and essential characteristics thereof. Therefore, thepresent embodiments are to be considered in all respects as illustrativeonly, the scope of the invention being indicated by the appended claimsrather than by the foregoing description.

I claim:

1. In a seat assembly having a relatively fixed seat member and a backmember mounted on said seat member for pivotal movement between aninclined position and an upright position; means for adjusting theposition of said back member comprising an extendable and contractableconnector assembly pivotally secured at its opposite ends to said seatmember and said back member respectively, and arranged to be extendedwhen said back member is moved to said inclined position, said connectorassembly comprising a housing connected to one of said members, a rodslidably received in said housing and connected to the other member, anoperating spring wholly within said housing biasing said connectorassembly to its contracted position, a plurality of juxtaposed centrallyapertured lock plates carried by said housing, said rod extendingthrough the apertures therein,

and said apertures being larger than said rod whereby said lock platescan be tilted relative to said rod, a fixed fulcrum rigid with saidhousing for preventing the movement of said lock plates toward the endof said housing from which the rod protrudes, said fulcrum being offsetto one side of the axis of said rod, a locking spring encircling saidrod and compressed between a fixed housing part and the side of saidlock plates remote from said fulcrum, said spring being operative totilt said lock plates around said fulcrum to lock said rod and saidhousing against extensible movement to lock said seat .back memberagainst movement toward its inclined position, said locking plates beingeffective to brake, but not lock, said rod against movement in acontracting direction whereby said seat back member may be moved towardits upright position, a cam member rotatably supported in said housingfor selective direct engagement with said locking plates on the side ofsaid rod opposite said fulcrum, and means for rotating said cam to movesaid lock plates against the force of said locking spring until saidlock plates are substantially normal to said rod whereby said rod may befreely moved in either direction.

2. The combination according to claim 1, wherein said fulcrum comprisesa pin carried by said housing and extending across said housingtransversely of the axis of said rod.

3. The combination according to claim 1, wherein said housing comprisesa pair of substantially identical flat members assembled in mirror imagerelationship.

4. The combination according to claim 1 together with a retainer fixedon said rod and wherein said operating spring is compressed between theend of said housing from which said rod extends and said retainer.

References Cited by the Examiner UNITED STATES PATENTS 2,579,305 12/1951Cushrnan 297-375 X 2,806,723 9/1957 Fairclough 248355 X 3,136,528 6/1964Eathough 240-355 X FRANK B. SHERRY, Primary Examiner.

I. S. PETRIE, R. B. FARLEY, Assistant Examiners.

1. IN A SEAT ASSEMBLY HAVING A RELATIVELY FIXED SEAT MEMBER AND A BACKMEMBER MOUNTED ON SAID SEAT MEMBER FOR PIVOTAL MOVEMENT BETWEEN ANINCLINED POSITION AND AN UPRIGHT POSITION; MEANS FOR ADJUSTING THEPOSITION OF SAID BACK MEMBER COMPRISING AN EXTENDABLE AND CONTRACTABLECONNECTOR ASSEMBLY PIVOTALLY SECURED AT ITS OPPOSITE ENDS TO SAID SEATMEMBER AND SAID BACK MEMBER RESPECTIVELY, AND ARRANGED TO BE EXTENDEDWHEN SAID BACK MEMBER IS MOVED TO SAID INCLINED POSITION, SAID CONNECTORASSEMBLY COMPRISING A HOUSING CONNECTED TO ONE OF SAID MEMBERS, A RODSLIDABLY RECEIVED IN SAID HOUSING AND CONNECTED TO THE OTHER MEMBER, ANOPERATING SPRING WHOLLY WITHIN SAID HOUSING BIASING SAID CONNECTINGASSEMBLY TO ITS CONTRACTED POSITION, A PLURALITY OF JUXTAPOSED CENTRALLYAPERTURED LOCK PLATES CARRIED BY SAID HOUSING, SAID ROD EXTENDINGTHROUGH THE APERTURES THEREIN, AND SAID APERTURES BEING LARGER THAN SAIDROD WHEREBY SAID LOCK PLATES CAN BE TILTED RELATIVE TO SAID ROD, A FIXEDFULCRUM RIGID WITH SAID HOUSING FOR PREVENTING THE MOVEMENT OF SAID LOCKPLATES TOWARD THE END OF SAID HOUSING FROM WHICH THE ROD PROTRUDES, SAIDFULCRUM BEING OFFSET TO ONE SIDE OF THE AXIS OF SAID ROD, A LOCKINGSPRING ENCIRCLING SAID ROD AND COMPRESSED BETWEEN A FIXED HOUSING PARTAND THE SIDE OF SAID LOCK PLATES REMOTE FROM SAID FULCRUM, SAID SPRINGBEING OPERATIVE TO TILT SAID LOCKPLATES AROUND SAID FULCRUM TO LOCK SAIDROD AND SAID HOUSING AGAINST EXTENSIBLE MOVEMENT TO LOCK SAID SEAT BACKMEMBER AGAINST MOVEMENT TOWRAD ITS INCLINED POSITION, SAID LOCKINGPLATES BEING EFFECTIVE TO BRAKE, BUT NOT LOCK, SAID ROD AGAINST MOVEMENTIN A CONTRACTING DIRECTION WHEREBY SAID SEAT BACK MEMBER MAY BE MOVEDTOWARD ITS UPRIGHT POSITION, A CAM MEMBER ROTATABLY SUPPORTED IN SAIDHOUSING FOR SELECTIVE DIRECT ENGAGEMENT WITH SAID LOCKING PLATES ON THESIDE OF SAID ROD OPPOSITE SAID FULCRUM, AND MEANS FOR ROTATING SAID CAMTO MOVE SAID LOCK PLATES AGAINST THE FORCE OF SAID LOCKING SPRING UNTILSAID LOCK PLATES ARE SUBSTANTIALLY NORMAL TO SAID ROD WHEREBY SAID RODMAY BE FREELY MOVED IN EITHER DIRECTION.